Materials Innovations: NDSU Research Team Coaxes Clays to Make Human Bone
The clays of the Red River Valley that cause structures to shift and buckle could actually hold the key to building better bones in humans.
Whether damaged by injury, disease or age, your body can’t create new bone—but science might be able to. Researchers at North Dakota State University (NDSU), Fargo, are making strides in tissue engineering, designing scaffolds that may lead to ways to regenerate bone. Published in the Journal of Biomedical Materials Research Part A,1 the research of Kalpana Katti, Ph.D.; Dinesh Katti, Ph.D.; and doctoral student Avinash Ambre includes a novel method that uses nanosized clays to make scaffolds to mineralize bone minerals such as hydroxyapatite.
The NDSU research team’s 3-D mesh scaffold is comprised of degradable materials that are compatible to human tissue. Over time, the cells generate bone and the scaffold deteriorates. As indicated in the NDSU team’s published scientific research from 2008 to 2013, the nanoclays enhance the scaffold’s mechanical properties by enabling the scaffold to bear load while bone generates. An interesting finding by the Katti group shows that the nanoclays also impart useful biological properties to the scaffold.
“The biomineralized nanoclays also impart osteogenic or bone-forming abilities to the scaffold to enable birth of bone,” said Kalpana Katti, distinguished professor of civil engineering at NDSU. “Although it would have been exciting to say that this finding had a ‘Eureka moment,’ this discovery was a methodical exploration of simulations and modeling, indicating that amino acid-modified nanoclays are viable new nanomaterials.” The work was initially published in the Journal of Biomacromoleculesin 2005.2 The current research findings in 2013 point toward the potential use of nanoclays for broader applications in medicine.
The NDSU’s group most recent study1 reports that nanoclays mediate human cell differentiation into bone cells and grow bone. The Katti research group uses amino acids—the building blocks of life—to modify clay structures, and the modified nanoclays coax new bone growth. “Our current research studies under way involve the use of bioreactors that mimic fluid/blood flow in the human body during bone tissue regeneration,” said Kalpana Katti.
There is some irony that the clay so prevalent in the Red River Valley could be integral to building bone in humans. Clay likes to swell and shrink, challenging engineers to build structures on the equivalent of shifting sands. Such clays can cause billions of dollars in damage to infrastructure worldwide, causing bridges and roads to buckle or buildings that shift or sink. But at the nanoscale level, substances exhibit very different properties. When it comes to serving as a component in bone scaffolding, nanoclays are a different story.
The Katti group at NDSU has pioneered the use of nanoclays in bone regeneration since 2008, with research results appearing in Biomedical Materials,3 ASME Journal of Nanotechnology for Engineering and Medicine,4 Materials Science and Engineering C,5 along with the February 2013 publication in the Journal of Biomedical Materials Research Part A.1
Bone tissue engineering represents important promise for regenerative medicine, according to Kalpana Katti. National Institutes of Health information shows that more than one million Americans have a hip or knee replaced each year. An aging population, in addition to orthopedic injuries of military veterans and diseases such as osteoporosis and arthritis, mean that the promise of scientific research to generate human bone could have far-reaching implications in the future.
NDSU, Fargo, N.D., is listed among the top 108 U.S. public and private universities in the Carnegie Commission on Higher Education’s category of Research Universities/Very High Research Activity. As a student-focused, land grant, research institution, NDSU is listed in the Top 100 research universities in the U.S. for R&D in computer science, chemistry, physical sciences, psychology, social sciences, and agricultural sciences, based on research expenditures reported to the National Science Foundation.
For more information, visit www.ndsu.edu/research.
1. Avinash H. Ambre, Dinesh R. Katti and Kalpana S. Katti, “Nanoclays Mediate Stem Cell Differentiation and Mineralized ECM Formation on Biopolymer Scaffolds,” Journal of Biomedical Materials Research Part A, 2013:101A:2644–2660.
2. D.R. Katti, P. Ghosh, S. Schmidt and K.S. Katti, “Mechanical Properties of Sodium Montmorillonite Interlayer Intercalcated with Amino Acids,” Biomacromolecules, (2005) 6, 3276-3282.
3. K.S. Katti, D.R. Katti, R. Dash, “Synthesis and Characterization of a Novel Chitosan/Montmorillonite/Hydroxyapatite Nanocomposite for Bone Tissue Engineering,” Biomedical Materials, (2008) 3, 034122.
4. A.H. Ambre, K.S. Katti, D.R. Katti, “Nanoclay Based Composite Scaffolds For Bone Tissue Engineering Applications,” ASME Journal of Nanotechnology for Engineering and Medicine, (2010) 1, 031013.
5. A.H. Ambre, K.S. Katti, D.R. Katti, “In situ Mineralized Hydroxyapatite with Amino Acid Modified Nanoclays as Novel Bone,” Biomaterials Materials Science and Engineering, (2011) C 31(5) 1017-1029.